Filters are used in filtration systems to filter impurities from fluid such as fuels or lubricants, prior to the fluid being used in a downstream system such as an engine or a transmission. The use of replaceable filters allows the user to replace a relatively inexpensive or easily removable wear part when the filter media, which collects and removes the impurities from the fluid, becomes spent, rather than requiring replacement of the entire filtration system.
In some instances, it may be desirable to pre-fill or “prime” the filter with the same fluid that is being filtered to prevent significant pockets of air within the fluid filtration system to prevent mis-operation or malfunctioning of the downstream system to which the fluid is being supplied. The fluid used to prime the filter may also be referred to as “priming fluid.”
Priming is typically performed by pouring some fluid into the filter through a dirty fluid inlet of the filter. During priming, it is beneficial to avoid allowing any of the priming fluid from getting downstream of the filter media, i.e. on a clean fluid side of the filter media. Thus, the priming fluid is filtered prior to being transported to and used by the downstream system. This prevents any contaminants or impurities that may be in the priming fluid from bypassing the filter media and ultimately entering the downstream system.
However, many filters include a dirty fluid inlet proximate a clean fluid outlet such that attempts to prime the filter through the dirty fluid inlet ultimately result in priming fluid entering the clean fluid outlet (i.e. downstream of the filter media and thus on the clean side). Thus, these impurities are undesirably permitted to ultimately travel to the downstream system that uses the fluid.
The present invention relates to improvements in filters and filter assemblies that prevent dirty or priming fluid from bypassing the filter media by entering the wrong fluid flow ports while priming a new filter and, particularly, a replacement filter.